| In order to realize the large-stroke and high-resolution movement of advanced manufacturing industry, the new liner piezoelectric motor that composes with the ultrasonic motor and the piezoelectric ceramic drive in the structure is proposed, which realizes the high precision, large stroke, high frequency precision positioning movement by making use of the micro motion of nano/micro scale compensated the error of macro motion. The performance of the drive control system directly influences the performance of the piezoelectric motor. Therefore, the paper proposes the large-stoke and high-resolution drive system that achieve the integration of the macro and micro drive system. The system realizes the seamless switching between AC and DC voltage and motion control.This paper introduces the operation mechanism of the piezoelectric linear motor, and the current driving scheme. According to the requirement of the piezoelectric linear motor,the drive control scheme of piezoelectric motor based on the cascade control of silicon controlled rectifier and DC-DC converter is proposed. According to the characteristics of multi-stage regulation circuit, a control strategy of two controllers is proposed, which makes the system obtain a high resolution, wide frequency band and high efficiency. The system uses DSP28335 as the core controller. the controller can realize the signal generator,the system monitor, the algorithm realization and so on, and carries on the precise control to the system in real time.The power drive system is mainly consist of two parts: hardware circuit and software programming. The drive circuit includes: Silicon controlled rectifier voltage regulator circuit and zero crossing signal detection circuit, which realizes the detection of the zero crossing signal and rectifying and regulates voltage;DC-DC converter circuit of half-bridge,which not only realizes voltage boosting and voltage isolation, but also reduces the volumeof the system by increasing the switching frequency; Half-bridge converter circuit, which not only realizes the seamless switching between the macro and micro drive, but also can control the motion of the piezoelectric motor by changing the opening frequency of MOSFET and phase; Isolation drive circuit, which realizes the electric isolation between the controller and the controlled object, drives the MOSFET, and amplifies driving signal;switching mode power circuit with multiple isolated output, which provides stable power to ensure the stable operation of the chip and controller.The software design includes: ADC conversion/calibration, control signal generation,control strategy design and output status monitoring and protection and so on. The control signal and the sampling signal are converted to digital signal, which can provide the input quantity and control the output state. According to the different control signals, the controller can outputs the adjustable voltage(0~600V), the adjustable phase(-90°~90 °)which the resolution is 1 degrees and adjustable frequency(20KHz~70KHz) AC voltage which the resolution is 10 Hz. the adjustable Duty ratio(0~100%)which the resolution is1%.According to the theoretical analysis of the system, each module is tested and verify.The experiments show that each module can run normally, and the performance of each module is improved obviously. Moreover, using the different types of piezoelectric motor to test the drive system,the results show that each piezoelectric motor can run normally and stably, Power drive system can not only drives the macro / micro pressure electric motor,and can also be used to separate drives the macro driven(such as: TRUM60) or micro motion(such as: cymbals driver), with good versatility. |
